From 1949 to 1977, 39 patients with localized malignant retrorectal tumors were treated at Memorial Sloan-Kettering Cancer Center. Chordomas were the most frequent histologic type (38 per cent of patients) followed by neurogenic tumors (15 per cent) chondrosarcomas, hemangiopericytomas, and embryonal adenocarcinomas (8 per cent each). Treatment consisted of surgical excision in 28 patients (18 of whom received adjuvant radiotherapy and/or chemotherapy). Ten patients were treated nonsurgically, receiving radiation and/or chemotherapy alone. Large tumors were most successfully managed by a combined surgical approach consisting of exploratory celiotomy, rectal mobilization, and bilateral hypogastric artery (with middle sacral artery and vein) ligation, followed by transsacral tumor excision with incontinuity sacrectomy. For all treated patients, survival at 5, 10, 15 and 20 years was 69 per cent, 50 per cent, 37 per cent and 20 per cent, respectively. Long-term disease-free survival (17 to 25 years post treatment) was noted in six patients. [Key words: Tumor(s), retrorectal, malignant; Tumor(s), treatment].